Provided by: libcoin60-doc_3.1.3-2_all bug

NAME

       SoGeoOrigin -

       The SoGeoOrigin class is used to specify an absolute geographic location against which
       geometry is referenced.

       FILE FORMAT/DEFAULTS:

SYNOPSIS

       #include <Inventor/nodes/SoGeoOrigin.h>

       Inherits SoNode.

   Public Member Functions
       SoGeoOrigin (void)
       virtual void doAction (SoAction *action)
       virtual void callback (SoCallbackAction *action)
       virtual void GLRender (SoGLRenderAction *action)
       virtual void getBoundingBox (SoGetBoundingBoxAction *action)
       virtual void getMatrix (SoGetMatrixAction *action)
       virtual void pick (SoPickAction *action)
       virtual void getPrimitiveCount (SoGetPrimitiveCountAction *action)

   Static Public Member Functions
       static void initClass (void)

   Public Attributes
       SoSFVec3d geoCoords
       SoMFString geoSystem

   Protected Member Functions
       virtual ~SoGeoOrigin ()

Detailed Description

       The SoGeoOrigin class is used to specify an absolute geographic location against which
       geometry is referenced.

       FILE FORMAT/DEFAULTS:

           GeoOrigin {
             geoSystem ['GD', 'WE']
             geoCoords 0 0 0
           }

       A common problem when dealing with geographic data is the reduced floating point precision
       you often get. UTM coordinates are often in the 10^5 a 10^6 magnitude, and this leaves
       very little precision for details at that position.

       The SoGeo nodes are therefore useful when you want to keep your data in its original
       system, but still get good floating point precision when rendering.

       Coin needs a local Cartesian coordinate system when rendering. When a SoGeoOrigin node is
       used, Coin will create a coordinate system at the SoGeoOrigin position, and all geometry
       (and the camera) in the scene graph will be projected into that coordinate system.

       The coordinate system will always have the Z axis point up from the ground. The Y axis
       will point towards the north pole, and the X-axis is found using the right hand rule.

       A scene graph should only contain one GeoOrigin node, and all geometry in the scene graph
       will, as stated earlier, be rendered relative to this position. This means that the
       precision will be best if the GeoOrigin position is as close to actual camera position as
       possible. If you move around on a large area, it might therefore be a good idea too
       actually move the GeoOrigin postition instead of the camera.

       To place geometry in the scene graph, you can either use an SoGeoSeparator node or an
       SoGeoCoordinate node. When using a GeoSeparator node, all geometry inside that separator
       will be rendered relative to its geo-system position and orientation, and you then use
       regular shapes and regular SoCoordinate3 nodes to specify data (the points in an
       SoCoordinate3 must be adjusted to be relative to the GeoSeparator position).

       The SoGeoCoordinate node on the other hand can contain double precision geo-coordinates,
       and that node will internally recalculate the double precison array to a single precision
       array which is relative to the SoGeoOrgin node.

       One note regarding UTM projections: Since it's quite common to assume a flat earth when
       working with UTM data, it's possible to supply a 'FLAT' keyword for UTM coordinate
       systems:

         GeoOrigin {
           geoSystem [ 'UTM', 'Z17', 'FLAT' ]
           geoCoords  846889 4313850 0
         }

       Example scene graph:

         GeoOrigin { geoSystem 'GD' geoCoords 40.77 -73.97 0 }

         GeoSeparator {
           # New York, NY
           geoSystem  'GD'
           geoCoords 40.67 -73.94 0

           BaseColor { rgb 0 1 0 }
           Cube { width 25000 height 25000 depth 25000 }
           Translation { translation 0 0 30000 }
           Text2 { string 'New York' }
         }

         GeoSeparator {
           # Los Angeles, CA
           geoSystem 'GD'
           geoCoords 34.11 -118.4 0

           BaseColor { rgb 1 0 0 }
           Cube { width 25000 height 25000 depth 25000 }
           Translation { translation 0 0 30000 }
           Text2 { string 'Los Angeles' }
         }

         GeoSeparator {
           # Washington, DC
           geoSystem [ 'UTM', 'Z17' ]
           geoCoords  846889 4313850 0

           BaseColor { rgb 0 1 1 }
           Cube { width 25000 height 25000 depth 25000 }

           Translation { translation 0 0 30000 }
           Text2 { string 'Washington' }
         }

         # add a small geogrid
         GeoCoordinate {
           geoSystem 'GD'
           point [
           32 -120 0,
           32 -110 0,
           32 -100 0,
           32 -90 0,
           32 -80 0,
           32 -70 0,

           34 -120 0,
           34 -110 0,
           34 -100 0,
           34 -90 0,
           34 -80 0,
           34 -70 0,

           36 -120 0,
           36 -110 0,
           36 -100 0,
           36 -90 0,
           36 -80 0,
           36 -70 0,

           38 -120 0,
           38 -110 0,
           38 -100 0,
           38 -90 0,
           38 -80 0,
           38 -70 0,

           40 -120 0,
           40 -110 0,
           40 -100 0,
           40 -90 0,
           40 -80 0,
           40 -70 0

           42 -120 0,
           42 -110 0,
           42 -100 0,
           42 -90 0,
           42 -80 0,
           42 -70 0
           ]
         }

         DrawStyle { style LINES }
         BaseColor {}
         ShapeHints { vertexOrdering COUNTERCLOCKWISE }
         QuadMesh { verticesPerRow 6 verticesPerColumn 6 }

       Since:
           Coin 2.5

Constructor & Destructor Documentation

   SoGeoOrigin::SoGeoOrigin (void) Constructor.
   SoGeoOrigin::~SoGeoOrigin () [protected, virtual] Destructor.

Member Function Documentation

   void SoGeoOrigin::initClass (void) [static] Sets up initialization for data common to all
       instances of this class, like submitting necessary information to the Coin type system.
       Reimplemented from SoNode.

   void SoGeoOrigin::doAction (SoAction *action) [virtual] This function performs the typical
       operation of a node for any action.
       Reimplemented from SoNode.

   void SoGeoOrigin::callback (SoCallbackAction *action) [virtual] Action method for
       SoCallbackAction.
       Simply updates the state according to how the node behaves for the render action, so the
       application programmer can use the SoCallbackAction for extracting information about the
       scene graph.

       Reimplemented from SoNode.

   void SoGeoOrigin::GLRender (SoGLRenderAction *action) [virtual] Action method for the
       SoGLRenderAction.
       This is called during rendering traversals. Nodes influencing the rendering state in any
       way or who wants to throw geometry primitives at OpenGL overrides this method.

       Reimplemented from SoNode.

   void SoGeoOrigin::getBoundingBox (SoGetBoundingBoxAction *action) [virtual] Action method for
       the SoGetBoundingBoxAction.
       Calculates bounding box and center coordinates for node and modifies the values of the
       action to encompass the bounding box for this node and to shift the center point for the
       scene more towards the one for this node.

       Nodes influencing how geometry nodes calculates their bounding box also overrides this
       method to change the relevant state variables.

       Reimplemented from SoNode.

   void SoGeoOrigin::getMatrix (SoGetMatrixAction *action) [virtual] Action method for
       SoGetMatrixAction.
       Updates action by accumulating with the transformation matrix of this node (if any).

       Reimplemented from SoNode.

   void SoGeoOrigin::pick (SoPickAction *action) [virtual] Action method for SoPickAction.
       Does common processing for SoPickAction action instances.

       Reimplemented from SoNode.

   void SoGeoOrigin::getPrimitiveCount (SoGetPrimitiveCountAction *action) [virtual] Action
       method for the SoGetPrimitiveCountAction.
       Calculates the number of triangle, line segment and point primitives for the node and adds
       these to the counters of the action.

       Nodes influencing how geometry nodes calculates their primitive count also overrides this
       method to change the relevant state variables.

       Reimplemented from SoNode.

Member Data Documentation

   SoSFVec3d SoGeoOrigin::geoCoords Used for specifying the geographic coordinates. For the GD
       system this should be <latitude> <longitude> <elevation>. For UTM it is <easting>
       <northing> <elevation>, and for GC it is simply <x> <y> <z>.
   SoMFString SoGeoOrigin::geoSystem Used to specify a spatial reference frame. Coin currently
       supports three different systems. Support for more systems might be added in the future.
       ·
       ·
       ·
       The 'GD' and 'UTM' systems can, for future support, have an ellipsoid specification. The
       default is 'WE' which is the WGS84 ellipsoid, the only ellipsoid currently supported in
       Coin.

Author

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